document.addEventListener('DOMContentLoaded', () => {
  const menuItems = document.querySelectorAll('.nav-item.dropdown');
  const subMenuItems = document.querySelectorAll('.dropdown-submenu');

  function addMenuEventListeners(items, isTopLevel) {
    items.forEach(item => {
      let timeout;

      function onMouseEnter() {
        clearTimeout(timeout);
        openMenu(item, isTopLevel);
      }

      function onMouseLeave() {
        timeout = setTimeout(() => {
          closeMenu(item);
        }, 500);
      }

      // Open on hover
      item.addEventListener('mouseenter', onMouseEnter);

      // Delayed close on mouse leave
      item.addEventListener('mouseleave', onMouseLeave);

      // Open and adjust position on click
      item.addEventListener('click', (e) => {
        e.stopPropagation(); // Prevents menus from closing when clicking inside
        if (item.classList.contains('open')) {
          closeMenu(item);
        } else {
          openMenu(item, isTopLevel);
        }
      });
    });
  }

  function addAllMenuEventListeners() {
    const updatedMenuItems = document.querySelectorAll('.nav-item.dropdown');
    const updatedSubMenuItems = document.querySelectorAll('.dropdown-submenu');
    addMenuEventListeners(updatedMenuItems, true);
    addMenuEventListeners(updatedSubMenuItems, false);
  }

  addAllMenuEventListeners();

  // Global click listener to close menus when clicking outside
  document.addEventListener('click', () => {
    [...menuItems, ...subMenuItems].forEach(item => closeMenu(item));
  });

  function openMenu(item, isTopLevel) {
    item.classList.add('open');
    const submenu = item.querySelector('.dropdown-menu');
    if (submenu) {
      submenu.style.display = 'block';
      submenu.style.opacity = '1';
      submenu.style.visibility = 'visible';
      adjustMenuPosition(submenu, item, isTopLevel);
    }
  }

  function closeMenu(item) {
    item.classList.remove('open');
    const submenu = item.querySelector('.dropdown-menu');
    if (submenu) {
      submenu.style.display = 'none';
      submenu.style.opacity = '0';
      submenu.style.visibility = 'hidden';
    }
  }

  function isSmallScreen() {
    return window.innerWidth < 992; // Bootstrap breakpoint for 'lg'
  }
    
  function adjustMenuPosition(submenu, parent, isTopLevel) {
    const rect = submenu.getBoundingClientRect();
    const parentRect = parent.getBoundingClientRect();

    const spaceAbove = parentRect.top;
    const spaceBelow = window.innerHeight - parentRect.bottom;
    const spaceLeft = parentRect.left;
    const spaceRight = window.innerWidth - parentRect.right;

    submenu.style.top = '';
    submenu.style.bottom = '';
    submenu.style.left = '';
    submenu.style.right = '';

    if (isTopLevel) {
      if (isSmallScreen() && spaceBelow < spaceAbove) {
        // For small screens: Open menu directly above the parent element
        submenu.style.top = 'auto';
        submenu.style.bottom = `${parentRect.height}px`; // Directly above the parent element
      } 
      // Top-level menu
      else if (spaceBelow < spaceAbove) {
        submenu.style.bottom = `${window.innerHeight - parentRect.bottom - parentRect.height}px`;
        submenu.style.top = 'auto';
      } else {
        submenu.style.top = `${parentRect.height}px`;
        submenu.style.bottom = 'auto';
      }
    } else {
      // Submenu
      const prefersRight = spaceRight >= spaceLeft;
      submenu.style.left = prefersRight ? '100%' : 'auto';
      submenu.style.right = prefersRight ? 'auto' : '100%';

      // Open upwards if there's no space below
      if (spaceBelow < spaceAbove) {
        submenu.style.bottom = `0`;
        submenu.style.top = `auto`;
      } else {
        submenu.style.top = `0`;
        submenu.style.bottom = `${parentRect.height}px`;
      }
    }
  }
});